本文中演示如何通过URLConnection获取Http响应Header信息

1.从响应中获得Header信息

URL obj = new URL("http://www.qiyadeng.com");

URLConnection conn = obj.openConnection();

Map> map = conn.getHeaderFields();

2.从响应Header中获取Server信息

Map> map = conn.getHeaderFields();

List server = map.get("Server");

完整的示例

package com.qiyadeng.http;

import java.net.URL;

import java.net.URLConnection;

import java.util.List;

import java.util.Map;

public class GetHttpResponseHeader {

public static void main(String[] args) {

try {

URL obj = new URL("http://www.qiyadeng.com");

URLConnection conn = obj.openConnection();

Map<String, List<String>> map = conn.getHeaderFields();

System.out.println("显示响应Header信息...n");

for (Map.Entry<String, List<String>> entry : map.entrySet()) {

System.out.println("Key : " + entry.getKey() +

" ,Value : " + entry.getValue());

}

System.out.println("n使用key获得响应Header信息 ...n");

List<String> server = map.get("Server");

if (server == null) {

System.out.println("Key 'Server' is not found!");

} else {

for (String values : server) {

System.out.println(values);

}

}

} catch (Exception e) {

e.printStackTrace();

}

}

}

输出

显示响应Header信息...

Key : null ,Value : [HTTP/1.1 200 OK]

Key : X-Pingback ,Value : [http://www.qiyadeng.com/xmlrpc.php]

Key : Date ,Value : [Sun, 10 Mar 2013 12:16:26 GMT]

Key : Transfer-Encoding ,Value : [chunked]

Key : Connection ,Value : [close]

Key : Content-Type ,Value : [text/html; charset=UTF-8]

Key : Server ,Value : [Apache/2.2.3 (CentOS)]

Key : X-Powered-By ,Value : [PHP/5.2.17]

使用key获得响应Header信息 ...

Apache/2.2.3 (CentOS)